Buggy code:
public class CommandlineJava implements Cloneable { private Commandline vmCommand = new Commandline ( ) ; private Commandline javaCommand = new Commandline ( ) ; private CommandlineJava . SysProperties sysProperties = new CommandlineJava . SysProperties ( ) ; private Path classpath = null ; private Path bootclasspath = null ; private String vmVersion ; private String maxMemory = null ; private Assertions assertions = null ; private boolean executeJar = false ; private boolean cloneVm = false ; public static class SysProperties extends Environment implements Cloneable { private Properties sys = null ; private Vector propertySets = new Vector ( ) ; public String [ ] getVariables ( ) throws BuildException { } public void addDefinitionsToList ( ListIterator listIt ) { } public int size ( ) { } public void setSystem ( ) throws BuildException { try { sys = System . getProperties ( ) ; Properties p = new Properties ( ) ; <START_BUG> for ( Enumeration e = sys . keys ( ) ; e . hasMoreElements ( ) ; ) { <END_BUG> Object o = e . nextElement ( ) ; p . put ( o , sys . get ( o ) ) ; } p . putAll ( mergePropertySets ( ) ) ; for ( Enumeration e = variables . elements ( ) ; e . hasMoreElements ( ) ; ) { Environment . Variable v = ( ( Environment . Variable ) ( e . nextElement ( ) ) ) ; p . put ( v . getKey ( ) , v . getValue ( ) ) ; } System . setProperties ( p ) ; } catch ( SecurityException e ) { throw new BuildException ( "Cannot<seq2seq4repair_space>modify<seq2seq4repair_space>system<seq2seq4repair_space>properties" , e ) ; } } public void restoreSystem ( ) throws BuildException { } public Object clone ( ) throws CloneNotSupportedException { } public void addSyspropertyset ( PropertySet ps ) { } private Properties mergePropertySets ( ) { } } public CommandlineJava ( ) { } public Argument createArgument ( ) { } public Argument createVmArgument ( ) { } public void addSysproperty ( Environment . Variable sysp ) { } public void addSyspropertyset ( PropertySet sysp ) { } public void setVm ( String vm ) { } public void setVmversion ( String value ) { } public void setCloneVm ( boolean cloneVm ) { } public Assertions getAssertions ( ) { } public void setAssertions ( Assertions assertions ) { } public void setJar ( String jarpathname ) { } public String getJar ( ) { } public void setClassname ( String classname ) { } public String getClassname ( ) { } public Path createClasspath ( Project p ) { } public Path createBootclasspath ( Project p ) { } public String getVmversion ( ) { } public String [ ] getCommandline ( ) { } private void addCommandsToList ( final ListIterator listIterator ) { } public void setMaxmemory ( String max ) { } public String toString ( ) { } public String describeCommand ( ) { } public String describeJavaCommand ( ) { } protected Commandline getActualVMCommand ( ) { } public int size ( ) { } public Commandline getJavaCommand ( ) { } public Commandline getVmCommand ( ) { } public Path getClasspath ( ) { } public Path getBootclasspath ( ) { } public void setSystemProperties ( ) throws BuildException { } public void restoreSystemProperties ( ) throws BuildException { } public CommandlineJava . SysProperties getSystemProperties ( ) { } public Object clone ( ) throws CloneNotSupportedException { } public void clearJavaArgs ( ) { } protected boolean haveClasspath ( ) { } protected boolean haveBootclasspath ( boolean log ) { } private boolean cloneBootclasspath ( ) { } private boolean isCloneVm ( ) { } }

Fix:
for ( Enumeration e = sys . propertyNames ( ) ; e . hasMoreElements ( ) ; ) {